I've got two DSs, age 6 and 9. ATM we have 2 family IPads, which they get to use for playing Minecraft, Terraria, Clash Royale etc etc, always in the family room and under (loose) supervision. Most of the games that they have are suitable for them both to play, I'm confident that they aren't accessing anything dodgy and that any chat DS1 participates in is within closed servers for him and his friends from school only. They play a lot of MC multiplayer together, which DS2 especially loves.
DS1 really wants a Nintendo 3DS. Loads of his friends have them, and TBH I'm not averse to him having one. But I think that DS2 is too young for one. Plus I think DS1 would be far more likely to want to go off and play alone in his bedroom, which I am keen to put off for as long as possible.
They are playing / gaming so nicely together at the moment I'm really loathe to disrupt the balance. But is it fair to deny DS1 a new 'toy' because DS2 can't have one as well?
How do you manage devices when you've got children of different ages?